Aircraft flight control system inertial measurement unit signal synthesis injection system and method

Abstract

The invention provides an aircraft flight control system inertial measurement unit signal synthesis injection system and method. The synthesis injection system comprises an inertial measurement unit mounted on a three-axis turntable, an aircraft six-degree-of-freedom simulation computer, inertial measurement unit signal synthesis injection equipment and a flight control computer. In a semi-physical simulation test stage, the system can synthesize a real inertial measurement unit signal output by an inertial measurement unit and a simulated inertial measurement unit signal output by an aircraft six-degree-of-freedom simulation computer according to an injection mode set by the aircraft six-degree-of-freedom simulation computer, and injects the synthesized signals into a flight control computer, so that closed-loop trajectory simulation of the flight control system is realized; signal level switching logic is adopted to directly output analog gyro and analog accelerometer signals to a flight control computer, so that the real inertial measurement unit signal cannot be delayed when reaching the flight control computer, and is consistent with the real signal state between an inertial measurement unit on an aircraft and the flight control computer; and the simulation computer does not need to obtain a real inertial measurement unit output signal, so that the test process is simplified, and the inertial measurement unit signal injection efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ground semi-physical simulation of aircraft control systems, and in particular relates to an aircraft flight control system inertial group signal synthesis injection system and method. Background Art

[0002] The inertial measurement unit (IMU), typically consisting of three orthogonally mounted gyroscopes and three orthogonally mounted accelerometers, is a critical sensor on aircraft. It senses the aircraft's angular velocity and acceleration, outputting signals to the flight control computer for position and attitude control, thereby achieving flight missions. The IMU's measurement errors directly impact the aircraft's control accuracy, so hardware-in-the-loop simulation of the IMU's physical circuits is essential for every aircraft development process.

[0003] During ground simulation, to assess flight deviations caused by IMU measurement errors, the IMU is typically mounted on the inner frame of a three-axis turntable. The three-axis turntable receives the aircraft's attitude angle signals from the aircraft's six-degree-of-freedom simulation computer and simulates the aircraft's spatial attitude. After physical perception, the IMU outputs three-axis gyroscope and three-axis acceleration signals to the flight control computer. Inertial group in-the-loop simulation primarily uses a three-axis attitude simulation turntable to excite the three gyros in the IMU. The output signal incorporates the inherent errors of the gyros themselves, resulting in a higher degree of confidence in the IMU's in-the-loop simulation model. The conventional process for mounting the IMU on a turntable for hardware-in-the-loop simulation is as follows:

[0004] Step 1: The six-degree-of-freedom simulator generates a three-axis posture command and sends it to the three-axis turntable;

[0005] Step 2: The three-axis turntable performs servo motion, and the outer ring, middle ring, and inner ring rotating frames rotate into place;

[0006] Step 3: The three gyroscopes in the IMU sense the attitude motion in three-dimensional space and output the measurement results;

[0007] Step 4: The three accelerometers in the IMU sense the local gravity acceleration and output the measurement results.

[0008] Step 5: The six-degree-of-freedom simulator collects the output signal of the real inertial group and parses the gyro data and acceleration data according to the communication protocol;

[0009] Step 6: The six-degree-of-freedom simulator repackages the acceleration data calculated by the mathematical model and the real gyroscope data collected in step 5 according to the communication protocol, recalculates the checksum, etc., and sends them to the flight control computer.

[0010] During the above-mentioned semi-physical simulation process, an additional serial port data reception process occurs at the signal level in step 5. At the same time, there is some additional time consumption between the two actions of receiving and sending on the simulation computer, which makes this "receive-synthesize-send" mode bring additional communication delays. Assume that the inertial group output signal adopts RS422 bus with a baud rate of 230400bps, and the 3-axis acceleration data and 3-axis angular velocity data adopt double type, totaling 48 bytes, plus the frame header, assuming that the frame header is 2 bytes and the checksum is 1 byte, totaling 51 bytes. The serial port uses UART to send one byte of 8-bit data, and additionally needs to send 1 start bit, 1 stop bit and 1 check bit, and usually 1 check bit is also configured. At least 2 idle bits are usually required between each byte sent by the serial port. The time required to send the above data is Fully digital simulators typically process data based on the simulation step size, assuming a simulation step size of 1ms. Upon receiving real inertial group data, it is not sent immediately. Instead, the serial port driver function must be called at each step by the numerical solver to send the data. The average delay follows a uniform distribution in the [0,1] interval, with a median of 0.5ms. When the real gyro data and simulated accelerometer data are repackaged and sent again, another 2.8755ms are required to send the data. From the above analysis, we can see that the total delay caused by the combined injection of the real gyro data and simulated acceleration data from the inertial group is:

[0011] 2.8755ms+0.5ms=3.2755ms

[0012] This delay is inconsistent with the actual transmission process of the aircraft system, resulting in deviations in the simulation conclusions. For low-speed, low-dynamic aircraft, a delay of 3.2755ms is acceptable. However, for high-speed, ultra-high-speed, or highly dynamic aircraft, this delay will affect the stability of the aircraft control system, making it impossible to accurately assess whether the inertial control unit design meets actual requirements.

[0013] There are currently two main solutions to the above-mentioned delay problem: the first is to reduce data transmission time by increasing the baud rate, but increasing the baud rate may increase the risk of communication errors; the other is to consider the delay when designing the control system and compensate for it during the control system design process, but this increases the difficulty of control system design. Summary of the Invention

[0014] The purpose of the present invention is to overcome the shortcomings of existing methods for solving the total delay problem caused by the merging and injection process of real gyroscope data of an inertial group and simulated accelerometer data, which may lead to the risk of communication errors or increase the difficulty of the control system design stage, and provide an aircraft flight control system inertial group signal synthesis injection system and method.

[0015] To achieve the above objectives, the technical solutions provided by the present invention are:

[0016] An aircraft flight control system inertial group signal synthesis injection system, the inertial group signal synthesis injection system comprising an inertial group mounted on a three-axis turntable, an aircraft six-degree-of-freedom simulation computer, an inertial group signal synthesis injection device, and a flight control computer;

[0017] The aircraft six-degree-of-freedom simulation computer is used to output simulated inertial group signals, simulation mode signals and aircraft attitude angle signals;

[0018] The inertial group is capable of outputting a real inertial group signal under the stimulation of the aircraft attitude angle signal output by the aircraft six-degree-of-freedom simulation computer;

[0019] The inertial group signal synthesis injection device can extract a simulated accelerometer signal from the simulated inertial group signal and a real gyroscope signal from the real inertial group signal. Furthermore, the device can determine a synthesis injection strategy based on a simulation mode signal output by the aircraft's six-degree-of-freedom simulation computer, and can send the real gyroscope signal and the simulated accelerometer signal to the flight control computer, or send the simulated inertial group gyroscope signal and the simulated accelerometer signal from the simulated inertial group signal to the flight control computer.

[0020] Furthermore, the inertial group signal synthesis injection device includes a driver, a processor and a high-speed three-to-one switch; the high-speed three-to-one switch includes a first signal transmission channel, a second signal transmission channel and a third signal transmission channel.

[0021] The signal output port of the inertial group outputs two paths, one of which is connected to the processor after passing through the driver; the other is directly connected to the third signal transmission channel of the high-speed three-to-one switch to inject the real inertial group signal into the flight control computer.

[0022] The analog signal output port of the aircraft six-degree-of-freedom simulation computer outputs two paths, one path is connected to the processor after passing through the driver; the other path is directly connected to the second signal transmission channel of the high-speed three-to-one switch, and is used to directly inject the simulated inertial group signal into the flight control computer; the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer is connected to the processor.

[0023] The processor is configured to calculate a byte count value of the real inertial group signal and control switching of the signal transmission channel of the high-speed three-to-one switch based on the byte count value of the real inertial group signal and the simulation mode level signal; and is configured to acquire and temporarily store the real gyroscope signal and the simulated accelerometer signal, calculate and output a checksum of the real gyroscope signal and the simulated accelerometer signal to the first signal transmission channel of the high-speed three-to-one switch.

[0024] The driver is used to convert the received real inertial group signal and the simulated inertial group signal into a serial port signal recognizable by the processor.

[0025] Furthermore, the processor includes an accelerometer data extraction module, a gyroscope data extraction module, a checksum calculation module, a switching logic module, and a counter module. The IMU signal output port has two output channels: one channel is connected to the gyroscope data extraction module and the counter module after passing through a driver; the other channel is directly connected to the third signal transmission channel of the high-speed three-to-one switch, used to inject the real IMU signal into the flight control computer.

[0026] The gyro data extraction module is used to extract and temporarily store the real gyro signal from the real inertial group signal, and transmit it to the verification and calculation module.

[0027] The analog signal output port of the aircraft six-degree-of-freedom simulation computer outputs two paths, one path is connected to the accelerometer data extraction module after passing through the driver; the other path is directly connected to the second signal transmission channel of the high-speed three-to-one switch, for directly injecting the simulated inertial group signal into the flight control computer; the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer is connected to the counter module.

[0028] The accelerometer data extraction module is used to extract and temporarily store the simulated accelerometer signal from the simulated inertial group signal, and transmit the extracted signal to the verification and calculation module.

[0029] The counter module is used to transmit the simulation mode level signal sent by the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer to the switching logic module, and is used to calculate the byte count value of the real inertial group signal.

[0030] The switching logic module is used to control the switching of the signal transmission channel of the high-speed three-to-one switch according to the simulation mode level signal result and the count value output by the counter module.

[0031] The checksum calculation module is used to calculate the checksum of the simulated accelerometer signal and the real gyroscope signal received in the same time period, and is used to inject the simulated accelerometer signal and the corresponding checksum into the flight control computer through the first signal transmission channel of the high-speed three-to-one switch.

[0032] Furthermore, the inertial group and the aircraft six-degree-of-freedom simulation computer are both provided with RS422 communication interfaces; the inertial group and the aircraft six-degree-of-freedom simulation computer are respectively communicatively connected to the driver and the processor via RS422 buses.

[0033] A method for synthesizing and injecting inertial group signals of an aircraft flight control system is implemented using the above-mentioned aircraft flight control system inertial group signal synthesis injection system. The method for synthesizing and injecting inertial group signals of an aircraft flight control system comprises the following steps:

[0034] Step 1: The aircraft's six-degree-of-freedom simulation computer sends a three-axis attitude command to the three-axis turntable, which performs servo motion. The inertial group (IMU) on the three-axis turntable outputs a real IMU signal to the IMU signal synthesis injection device.

[0035] Step 2: The aircraft six-degree-of-freedom simulation computer outputs a simulated inertial group signal and a simulation mode signal; the simulated inertial group signal includes a simulated gyroscope signal and a simulated accelerometer signal;

[0036] Step 3: The inertial group signal synthesis and injection device obtains the simulation mode signal and the simulated inertial group signal output by the aircraft's six-degree-of-freedom simulation computer, and injects the real inertial group signal and the simulated inertial group signal output during the same period, or the simulated inertial group signal, into the flight control computer based on the state of the simulation mode signal. If the simulation mode signal is a low-level signal, execute step 4; if the simulation mode signal is a high-level signal, execute step 5.

[0037] Step 4: directly injecting the simulated inertial group signal into the flight control computer through the second signal transmission channel of the inertial group signal synthesis injection device;

[0038] Step 5: The inertial group signal synthesis injection device synthesizes the simulated accelerometer signal output in the same period and the real gyroscope signal in the real inertial group signal and injects them into the flight control computer.

[0039] Furthermore, the step 5 specifically includes the following sub-steps:

[0040] Step 5.1: The inertial group signal synthesis injection device initializes the real gyro signal byte count value to zero;

[0041] Step 5.2: Turn on the third signal transmission channel of the inertial group signal synthesis injection device, and send the frame header and bytes of the current frame data of the real gyro signal to the flight control computer through the third signal transmission channel;

[0042] Step 5.3: Extract and temporarily store the current frame data and corresponding bytes of the real gyroscope signal;

[0043] Step 5.4: Count the bytes of the current frame data of the real gyro signal. If the total value of the real gyro signal bytes is less than the set threshold of the gyro signal bytes, then continue the operation of step 5.2.

[0044] If the total value of the gyro signal bytes is equal to the gyro signal byte setting threshold, the first signal transmission channel of the inertial group signal synthesis injection device is switched on to the flight control computer, the current frame data of the simulated accelerometer signal in the simulated inertial group signal is extracted, the bytes of the current frame data of the simulated accelerometer signal are counted, and the checksum of the current frame data of the simulated accelerometer signal and the current frame data of the real gyro signal output in step 5.3 is recalculated; and the byte count value of the current frame data of the simulated accelerometer signal is compared with the accelerometer signal byte setting threshold:

[0045] If the byte count value of the current frame data of the analog accelerometer signal is less than the accelerometer signal byte setting threshold, injecting the current frame data of the analog accelerometer signal and the corresponding checksum into the flight control computer via the first signal transmission channel; if the byte count value of the current frame data of the analog accelerometer signal is equal to the accelerometer signal byte setting threshold, returning to step 5.1;

[0046] Step 5.5: Follow the process from Step 5.1 to Step 5.4 to inject the next frame of data of the real gyroscope signal and the simulated accelerometer signal into the flight control computer.

[0047] Furthermore, the real inertial group signal and the simulated inertial group signal are transmitted using an RS422 bus; in step 5.4, the total number of gyro signal bytes includes the total number of bytes of 2 frame headers and 3 double-type gyro signals.

[0048] Furthermore, in step 5.4, the gyro signal byte threshold is set to 26 bytes, and the accelerometer signal byte threshold is set to 25 bytes.

[0049] The advantages of the present invention are:

[0050] 1. The inertial group signal synthesis injection device designed in the present invention includes a driver, a processor, and a high-speed three-to-one switch. The processor includes an accelerometer data extraction module, a gyroscope data extraction module, a checksum calculation module, a switching logic module, and a counter module. The inertial group signal synthesis injection system of the present invention can switch the output of the real gyroscope signal output by the inertial group with the simulated inertial group signal (including the simulated gyroscope signal and the simulated accelerometer signal) output by the aircraft's six-degree-of-freedom simulation computer by configuring the simulation mode (high-level mode signal and low-level mode signal) without changing the original overall test connection method, thereby realizing the combined injection of "simulated gyroscope signal + simulated accelerometer signal" or "real gyroscope signal + simulated accelerometer signal". The two injection modes can be freely switched according to actual test requirements, reducing test steps and accelerating test progress.

[0051] 2. When the inertial group signal synthesis injection system of the present invention synthesizes and injects the inertial group signals (real signals and simulated signals) into the flight control computer, it directly outputs the simulated gyroscope signals and simulated accelerometer signals to the flight control computer through a designed switching logic module. This ensures that the real inertial group signals reach the flight control computer without delay, and remains consistent with the actual signal state between the inertial group and the flight control computer on the actual aircraft. This solves the communication delay problem caused by the traditional data transmission process of "real inertial group data reception - protocol analysis - repackaging - resending".

[0052] 3. The present invention saves one serial port resource of the simulation computer. The aircraft's six-degree-of-freedom simulation computer does not need to receive the actual gyroscope signal output by the inertial group, but only needs to generate a simulated inertial group signal. This greatly improves the efficiency of inertial group signal synthesis injection and further enhances the stability of the aircraft control system. It has a significant effect, especially for high-speed, ultra-high-speed, and highly dynamic aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0054] Figure 1 This is a schematic diagram of the connections of the inertial group mounted on a three-axis turntable for hardware-in-the-loop simulation.

[0055] Figure 2 This is a hardware configuration diagram of the inertial group signal synthesis injection device in the present invention;

[0056] Figure 3 It is a logic block diagram of internal signal synthesis injection of the processor in the present invention;

[0057] Figure 4 It is a common data frame format for real inertial group to send data via RS422;

[0058] Figure 5 It is a specific flow chart of the method of the present invention to realize two injection modes of "simulated gyroscope signal + simulated accelerometer signal" or "true gyroscope signal + simulated accelerometer signal". DETAILED DESCRIPTION

[0059] The following describes in detail embodiments of the present invention. The embodiments are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0060] Reference Figure 1-Figure 3This embodiment provides an inertial group signal synthesis and injection system for an aircraft flight control system, used during the hardware-in-the-loop simulation test phase of the aircraft flight control system. The system includes an inertial group (IMU), an aircraft six-degree-of-freedom (6DOF) simulation computer, an IMU signal synthesis and injection device, and a flight control computer. The IMU is mounted on the inner frame of a three-axis turntable. The three-axis turntable can simulate the aircraft's spatial attitude after receiving the aircraft attitude angle signal from the aircraft six-degree-of-freedom simulation computer. After physical perception, the IMU can periodically output a real three-axis gyroscope signal to the flight control computer. The aircraft six-degree-of-freedom simulation computer is used to output a simulated IMU signal, a simulation mode signal, and an aircraft attitude angle signal. The IMU signal synthesis and injection device can extract a simulated accelerometer signal from the simulated IMU signal and a real gyroscope signal from the real IMU signal. Furthermore, the device can determine a synthesis and injection strategy based on the simulation mode signal output by the aircraft six-degree-of-freedom simulation computer, and can either send the real gyroscope signal and the simulated accelerometer signal to the flight control computer, or send the simulated IMU gyroscope signal and the simulated accelerometer signal from the simulated IMU signal to the flight control computer.

[0061] Specifically, the simulation mode of the aircraft's six-degree-of-freedom simulation computer is represented by level signals, including two types of simulation mode signals: "high level" and "low level." The aircraft's six-degree-of-freedom simulation computer's simulation mode signal output interface can output different level signals based on different simulation mode requirements. It processes two input signals (the gyro signal of the real inertial group and the accelerometer signal of the simulated inertial group) and outputs the inertial group signal to the flight control computer. The "high level" mode combines the real inertial group gyro signal with the simulated inertial group accelerometer signal to form an inertial group signal, which is then transmitted to the flight control computer. The "low level" mode directly transmits the angular velocity and acceleration signals of the simulated inertial group to the flight control computer.

[0062] Specifically, the inertial group signal synthesis injection device includes a driver, a processor, and a high-speed three-to-one switch. The high-speed three-to-one switch includes a first signal transmission channel, a second signal transmission channel, and a third signal transmission channel. The processor (single-chip microcomputer, DSP, MCU, or FPGA) is used to merge the real inertial group signal and the simulated inertial group signal, and inject the merged signal into the flight control computer; the processor is equipped with an accelerometer data extraction module, a gyroscope data extraction module, a checksum calculation module, a switching logic module, and a counter module. Taking the typical RS422 interface output as an example, the specific functions of each module and the signal transmission relationship are described as follows:

[0063] The processor has three signal input interfaces and one signal output interface. These three signal input interfaces include the real IRU signal input interface, the simulated IRU signal input interface for the simulator, and the simulation mode setting level signal input interface. The IRU signal output port outputs two channels: one channel is connected to the gyro data extraction module and the counter module after passing through the driver; the other channel is directly connected to the third signal transmission channel of the high-speed three-to-one switch, which is used to inject the real IRU signal into the flight control computer.

[0064] The gyro data extraction module is used to extract and temporarily store the real gyro signal from the real inertial group signal, and output the frame header and real gyro data to the verification and calculation module.

[0065] The analog signal output port of the aircraft's six-degree-of-freedom simulation computer outputs two channels. One channel is connected to the accelerometer data extraction module after passing through the driver; the other channel is directly connected to the second signal transmission channel of the high-speed three-to-one switch, which is used to directly inject the simulated inertial group signal into the flight control computer; the simulation mode signal output port of the aircraft's six-degree-of-freedom simulation computer is connected to the counter module.

[0066] The accelerometer data extraction module is used to extract and temporarily store the analog accelerometer signal from the analog inertial group signal according to the protocol content, and transmit it to the verification and calculation module.

[0067] The switching logic module is used to control the signal transmission channel of the high-speed three-to-one switch based on the simulation mode level signal results and the count value output by the counter module. Specifically, when the counter module count value is less than 26 bytes, the switching logic module will connect the output to the "frame header and real gyroscope data" signal transmission channel of the high-speed three-to-one switch, injecting the real gyroscope data into the flight control computer. When the counter module count value equals 26 bytes (including two frame headers and three double-type gyroscope signals), the switching logic module will switch the output to the "simulated accelerometer and checksum" signal transmission channel of the high-speed three-to-one switch, injecting the simulated accelerometer signal into the flight control computer. At the same time, the switching logic module will send a control signal to the checksum calculation module during the switching.

[0068] The checksum calculation module is used to calculate the checksum of the simulated accelerometer signal and the real gyroscope signal received in the same period, and to inject the simulated accelerometer signal and the corresponding checksum into the flight control computer through the first signal transmission channel of the high-speed three-to-one switch.

[0069] The counter module transmits the simulation mode level signal from the aircraft's 6DOF simulation computer's simulation mode signal output port to the switching logic module, where it calculates the byte count of the real inertial group signal. When the counter module's count equals the total packet length (51 bytes), the count is reset to zero, and the output port is reconnected to the "frame header and real gyro signal" signal transmission channel of the high-speed three-to-one switch.

[0070] The driver is used to convert the received real and simulated inertial group signals into serial signals recognizable by the processor. Both the inertial group and the aircraft's six-degree-of-freedom simulation computer are equipped with RS422 communication interfaces. The inertial group and the aircraft's six-degree-of-freedom simulation computer are connected to the driver and processor via the RS422 bus, respectively. The inertial group and the aircraft's six-degree-of-freedom simulation computer can respectively send the real and simulated inertial group signals directly to the two input channels of the high-speed three-to-one switch via the RS422 serial port signals. The processor outputs another RS422 signal to the other input channel of the high-speed three-to-one switch. The processor then outputs a digital signal to control the switching of the signal transmission channels of the high-speed three-to-one switch. The switching time does not exceed one RS422 bit width.

[0071] This embodiment mainly explains how to synthesize the two types of signals, real inertial group output and simulated inertial group output. It should be noted that the three-axis gyroscope and three-axis accelerometer contained in the inertial group are two independent types of sensors. The data they sense is usually quantized into double type, totaling 6 quantities. The inertial group output signal is currently commonly used in the form of RS422 serial port. The more representative communication protocols are as follows: Figure 4 Assume that two simulation modes are represented in the form of levels:

[0072] High level: represents the synthetic injection mode of the real gyroscope signal and the simulated accelerometer signal.

[0073] Low level: represents the synthetic injection mode of the analog gyroscope signal and the analog accelerometer signal.

[0074] Reference Figure 5 The following describes the detailed processing of the inertial group signal synthesis injection method of the present invention by taking the typical RS422 interface output of the inertial group as an example:

[0075] Step 1: The aircraft's six-degree-of-freedom simulation computer sends a three-axis attitude command to the three-axis turntable, which performs servo motion; the inertial group on the three-axis turntable outputs a real inertial group signal to the inertial group signal synthesis injection device.

[0076] Step 2: The aircraft's six-degree-of-freedom simulation computer outputs a simulated inertial group signal and a simulation mode signal; the simulated inertial group signal includes a simulated gyroscope signal and a simulated accelerometer signal.

[0077] Step 3: The IMU signal synthesis injection device obtains the simulation mode signal and simulated IMU signal output by the aircraft's 6-DOF simulation computer. Based on the simulation mode signal status, it injects the real IMU signal and the simulated IMU signal output during the same period, or the simulated IMU signal, into the flight control computer. If the simulation mode signal is low, it indicates that the user has configured the injection method to be "simulated gyroscope signal and simulated accelerometer signal," and the process proceeds to Step 4. If the simulation mode signal is high, it indicates that the user has configured the injection method to be "simulated gyroscope signal and simulated accelerometer signal," and the process proceeds to Step 5.

[0078] Step 4: Switch the signal transmission channel of the high-speed three-to-one switch to channel 2, and directly inject the simulated inertial group signal into the flight control computer;

[0079] Step 5: The IMU signal synthesis injection device synthesizes the simulated accelerometer signal output during the same period with the real gyro signal in the real IMU signal and injects it into the flight control computer. This includes the following sub-steps:

[0080] Step 5.1: The counter module initializes the real three-axis gyroscope signal byte count value to zero.

[0081] Step 5.2: The switching logic module controls the high-speed three-to-one switch to switch the signal transmission channel to its channel 3, and sends the frame header and bytes of the current frame data of the real gyro signal to the flight control computer through channel 3 of the high-speed three-to-one switch.

[0082] Step 5.3: The gyro data extraction module extracts and temporarily stores the current frame data of the real gyro signal, and outputs the bytes of the current frame data of the real gyro signal to the checksum calculation module.

[0083] Step 5.4: At the same time, the counter module counts the bytes of the current frame data of the real three-axis gyroscope signal. When the total value of the real three-axis gyroscope signal bytes is less than 26 (including 2 frame headers and 3 double-type gyroscope signals), the signal transmission channel of the high-speed three-selection switch is always kept as channel 3.

[0084] When the total number of bytes in the actual three-axis gyroscope signal equals 26 bytes, the signal transmission channel of the high-speed three-to-one switch is switched to channel 1, and a trigger signal is simultaneously sent to the checksum calculation module. The checksum calculation module begins outputting the simulated acceleration signal. The checksum calculation module reads the temporarily stored acceleration data parsed from the simulated inertial group signal and the actual gyroscope data parsed from the actual inertial group during the same period. Based on the checksum calculation method, the checksum is recalculated and the number of bytes in the current frame of the simulated acceleration signal is determined. If the byte count value of the current frame of the simulated accelerometer signal is less than 25 bytes, the current frame of the simulated accelerometer signal and the corresponding checksum are transmitted to the flight control computer via channel 1 of the high-speed three-to-one switch. If the byte count value of the current frame of the simulated accelerometer signal is equal to 25 bytes (i.e., the total data packet length is 51 bytes), the process returns to step 5.1, the counter in the counter module is reset, and the output of the high-speed three-to-one switch is reconnected to channel 3.

[0085] Step 5.5: Follow the process from Step 5.1 to Step 5.4 to combine the real gyro signal with the next frame of simulated accelerometer signal and send it to the flight control computer.

[0086] The aircraft flight control system inertial group signal synthesis injection method provided in this embodiment is designed to synthesize the gyro signal of the real inertial group with the simulated accelerometer signal output by the flight trajectory simulation computer for the test mode in which the inertial group is installed on a three-axis turntable. No delay is generated during the synthesis process, thereby ensuring the authenticity of the simulation. At the same time, the method can also realize two mode tests of "simulated gyro signal + simulated accelerometer signal" or "real gyro signal + simulated accelerometer signal" by configuring the simulation mode without changing the test connection method. The above two test modes can be switched according to the test requirements, reducing the test steps and accelerating the test progress.

[0087] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present invention, and these modifications or replacements should all be included in the scope of protection of the present invention.

Claims

1. An aircraft flight control system inertial group signal synthesis injection system, characterized in that: The inertial group signal synthesis injection system includes an inertial group installed on a three-axis turntable, an aircraft six-degree-of-freedom simulation computer, an inertial group signal synthesis injection device and a flight control computer; The aircraft six-degree-of-freedom simulation computer is used to output simulated inertial group signals, simulation mode signals and aircraft attitude angle signals; The inertial group is capable of outputting a real inertial group signal under the stimulation of the aircraft attitude angle signal output by the aircraft six-degree-of-freedom simulation computer; The inertial group signal synthesis injection device is capable of extracting a simulated accelerometer signal from the simulated inertial group signal, and extracting a real gyroscope signal from the real inertial group signal; The invention can also determine a synthetic injection strategy according to the simulation mode signal output by the six-degree-of-freedom simulation computer of the aircraft, and send the real gyro signal and the simulated accelerometer signal into the flight control computer, or send the simulated inertial group gyro signal and the simulated accelerometer signal in the simulated inertial group signal into the flight control computer.

2. The aircraft flight control system inertial group signal synthesis injection system according to claim 1, characterized in that: The inertial group signal synthesis injection device includes a driver, a processor and a high-speed three-to-one switch; The high-speed three-to-one switch includes a first signal transmission channel, a second signal transmission channel and a third signal transmission channel; The signal output port of the IMU outputs two channels, one of which is connected to the processor after passing through the driver; the other is directly connected to the third signal transmission channel of the high-speed three-to-one switch, for injecting the real IMU signal into the flight control computer; The analog signal output port of the aircraft six-degree-of-freedom simulation computer outputs two paths, one path is connected to the processor after passing through the driver; the other path is directly connected to the second signal transmission channel of the high-speed three-to-one switch, for directly injecting the simulated inertial group signal directly into the flight control computer; the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer is connected to the processor; The processor is used to calculate the byte count value of the real inertial group signal, and to control the switching of the signal transmission channel of the high-speed three-to-one switch according to the byte count value of the real inertial group signal and the simulation mode level signal; Used to obtain and temporarily store the real gyroscope signal and the simulated accelerometer signal, calculate and output the checksum of the real gyroscope signal and the simulated accelerometer signal to the first signal transmission channel of the high-speed three-to-one switch; The driver is used to convert the received real inertial group signal and the simulated inertial group signal into a serial port signal recognizable by the processor.

3. The aircraft flight control system inertial group signal synthesis injection system according to claim 2, characterized in that: The processor includes an accelerometer data extraction module, a gyroscope data extraction module, a checksum calculation module, a switching logic module and a counter module; The signal output port of the IMU outputs two paths, one of which is connected to the gyro data extraction module and the counter module respectively after passing through the driver; the other is directly connected to the third signal transmission channel of the high-speed three-to-one switch, for injecting the real IMU signal into the flight control computer; The gyro data extraction module is used to extract and temporarily store the real gyro signal from the real inertial group signal, and transmit it to the verification and calculation module; The analog signal output port of the aircraft six-degree-of-freedom simulation computer outputs two paths, one path being connected to the accelerometer data extraction module after passing through the driver; the other path being directly connected to the second signal transmission channel of the high-speed three-to-one switch for directly injecting the simulated inertial group signal into the flight control computer; the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer is connected to the counter module; The accelerometer data extraction module is used to extract and temporarily store the analog accelerometer signal from the analog inertial group signal, and transmit it to the verification and calculation module; The counter module is used to transmit the simulation mode level signal sent by the simulation mode signal output port of the aircraft six-degree-of-freedom simulation computer to the switching logic module, and to calculate the byte count value of the real inertial group signal; The switching logic module is used to control the switching of the signal transmission channel of the high-speed three-to-one switch according to the simulation mode level signal result and the count value output by the counter module; The checksum calculation module is used to calculate the checksum of the simulated accelerometer signal and the real gyroscope signal received in the same time period, and is used to inject the simulated accelerometer signal and the corresponding checksum into the flight control computer through the first signal transmission channel of the high-speed three-to-one switch.

4. The aircraft flight control system inertial group signal synthesis injection system according to claim 3, characterized in that: The inertial group and the aircraft six-degree-of-freedom simulation computer are both provided with RS422 communication interfaces; the inertial group and the aircraft six-degree-of-freedom simulation computer are respectively connected to the driver and the processor via RS422 buses.

5. A method for synthesizing and injecting inertial group signals of an aircraft flight control system, characterized in that: The method for synthesizing and injecting inertial group signals of an aircraft flight control system according to any one of claims 1 to 4 is implemented, and the method comprises the following steps: Step 1: The aircraft's six-degree-of-freedom simulation computer sends a three-axis attitude command to the three-axis turntable, which performs servo motion. The inertial group (IMU) on the three-axis turntable outputs a real IMU signal to the IMU signal synthesis injection device. Step 2: The aircraft six-degree-of-freedom simulation computer outputs a simulated inertial group signal and a simulation mode signal; the simulated inertial group signal includes a simulated gyroscope signal and a simulated accelerometer signal; Step 3: The inertial group signal synthesis and injection device obtains the simulation mode signal and the simulated inertial group signal output by the aircraft's six-degree-of-freedom simulation computer, and injects the real inertial group signal and the simulated inertial group signal output during the same period, or the simulated inertial group signal, into the flight control computer based on the state of the simulation mode signal. If the simulation mode signal is a low-level signal, execute step 4; if the simulation mode signal is a high-level signal, execute step 5. Step 4: directly injecting the simulated inertial group signal into the flight control computer through the second signal transmission channel of the inertial group signal synthesis injection device; Step 5: The inertial group signal synthesis injection device synthesizes the simulated accelerometer signal output in the same period and the real gyroscope signal in the real inertial group signal and injects them into the flight control computer.

6. The method for synthesizing and injecting inertial group signals of an aircraft flight control system according to claim 5, characterized in that: The step 5 includes the following sub-steps: Step 5.1: The inertial group signal synthesis injection device initializes the real gyro signal byte count value to zero; Step 5.2: Turn on the third signal transmission channel of the inertial group signal synthesis injection device, and send the frame header and bytes of the current frame data of the real gyro signal to the flight control computer through the third signal transmission channel; Step 5.3: Extract and temporarily store the current frame data and corresponding bytes of the real gyroscope signal; Step 5.4: Count the bytes of the current frame data of the real gyro signal. If the total value of the real gyro signal bytes is less than the set threshold of the gyro signal bytes, then continue the operation of step 5.

2. If the total value of the gyro signal bytes is equal to the gyro signal byte setting threshold, the first signal transmission channel of the inertial group signal synthesis injection device is switched on to the flight control computer, the current frame data of the simulated accelerometer signal in the simulated inertial group signal is extracted, the bytes of the current frame data of the simulated accelerometer signal are counted, and the checksum of the current frame data of the simulated accelerometer signal and the current frame data of the real gyro signal output in step 5.3 is recalculated; and the byte count value of the current frame data of the simulated accelerometer signal is compared with the accelerometer signal byte setting threshold: If the byte count value of the current frame data of the analog accelerometer signal is less than the accelerometer signal byte setting threshold, injecting the current frame data of the analog accelerometer signal and the corresponding checksum into the flight control computer via the first signal transmission channel; if the byte count value of the current frame data of the analog accelerometer signal is equal to the accelerometer signal byte setting threshold, returning to step 5.1; Step 5.5: Follow the process from Step 5.1 to Step 5.4 to inject the next frame of data of the real gyroscope signal and the simulated accelerometer signal into the flight control computer.

7. The method for synthesizing and injecting inertial group signals of an aircraft flight control system according to claim 5, characterized in that: The real inertial group signal and the simulated inertial group signal are transmitted using the RS422 bus. In step 5.4, the total gyro signal byte value includes the total number of bytes of 2 frame headers and 3 double-type gyro signals.

8. The method for synthesizing and injecting inertial group signals of an aircraft flight control system according to claim 7, characterized in that: In step 5.4, the gyro signal byte threshold is set to 26 bytes, and the accelerometer signal byte threshold is set to 25 bytes.

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